Interview by Richard Marshall.

 

'European freedom of movement was the third element that allowed me to become a philosopher. Coming from a village in Italy, being an only child, and a woman, the idea of me going abroad to study for a PhD was practically unheard of. And once again, had it not been for the value my parents placed on education, as well as for the possibility of free movement across Europe, I most certainly would never have landed in the UK.'

'Looking at Pauli’s scientific correspondence and the way he originally introduced the principle in a letter to Alfred Landé in 1924, it was clear that it was a purely phenomenological rule to explain some puzzling phenomena in spectroscopy on which Pauli and colleagues had been working for years. Heisenberg referred to it teasingly as Pauli’s “Verbot”; and it was only with Dirac that it became known as “Pauli’s exclusion principle” in 1926. How did a phenomenological rule eventually become a scientific principle?'

'How can we—as epistemic agents—come to encounter nature as lawful? Which epistemic faculty underpins our ability to recognise that some empirical regularities are not just accidentally so, but are effectively the manifestation of nature’s lawfulness? This is an epistemological question, not a metaphysical one.'

'Kant’s view on the lawfulness of nature is central to his Critical project. For he regards the faculty of understanding as the ultimate source of the lawfulness of nature. In Kant’s view, our ability to see, for example, two appearances (e.g., my cup of coffee falling and a stain forming on the floor) as causally connected (and not just as some kind of Humean juxtaposition of events) is due to one of our principles of the faculty of understanding, namely causality.'

'The metaphysical question that looms large is then: how can one be a realist about science (and believe, for example, that scientific theories are approximately true) while also acknowledging that our scientific knowledge is inevitably situated? The epistemic humility behind perspectivism seems to be in stark contrast with the God’s-eye view presupposed by the realist quest for truth.'

'Being able to wear different hats depending on whether the interlocutors are physicists, historians, or philosophers is methodologically very challenging, and it is also an intellectually risky enterprise. We live in an era where not even within a single discipline (say, philosophy) can scholars easily communicate or build bridges because of the very different languages, intellectual priorities, and research goals present in different sub-fields.'

Michela Massimi is a philosopher of science. She works in the broad area of history and philosophy of modern physics and she has written extensively on Kant’s philosophy of natural science, on laws of nature, and more recently on realism and perspectivism in science. She was Co-Editor-in-Chief of The British Journal for the Philosophy of Science (2011–16), and she is currently Vice President of the European Philosophy of Science Association(2015–019). She is the PI on a five-year ERC Consolidator grant on Perspectival Realism: Science, Knowledge and Truth from a Human Vantage Point(2016–20). She is the recipient of the 2017 Royal Society Wilkins--Bernal--Medawar Medal Lecturefor her interdisciplinary interest in and communication of science and philosophy; and in 2018 she was elected Fellow of the Royal Society of Edinburgh. Here she discusses, among other things, her early love for philosophy; how she began her research on the history of early quantum theory; her rediscovery of metaphysics in Kant’s philosophy of nature; challenges and rewards of interdisciplinary research; and questions about evidence, truth, and perspectivism in science and why they matter for contemporary society….

3:AM:What made you become a philosopher?

Michela Massimi: The combination of three main factors: my parents; the Italian state school system; and European freedom of movement. I believe my story is the story of many Europeans holding positions in universities in the UK and across Europe. And so, for what it’s worth, here it is.

My parents first. I read in your 3AMinterviews how love for philosophy often originates at home, maybe around the kitchen table, from academic parents engaged in intellectual discussions. Mine is a different story. I grew up in the Italian countryside, in a small village near Rome. Neither of my parents gained a university degree. My grandparents worked in the fields—the lifestyle of rural Italy (up until the 1970s really) did not exactly facilitate access to university education for children without a privileged background. The village where I grew up as a child did not have a bookshop at the time or a public library, for that matter.

But there were novels at home that my father would buy in bookstores in Rome. He was keen on the Italian novelist Ignazio Silone, and suggested that I should read Silone’s Fontamarawhen I was 12 years old. The novel recounts the story of central Italian peasants (around the 1930s) who lived in the fictional rural village that gives the book its name. Fontamara was not exactly the kind of book one would naturally expect a 12-year-old child to enjoy reading. And, indeed, I did not particularly enjoy reading it at the time. A key episode in the novel remains in my memory to this day: a local wealthy landowner struck a deal with the peasants (the “cafoni”, as Silone refers to them in the book, a derogatory Italian expression to refer to those without education and literacy). The deal consisted in deviating the local watercourse to irrigate the landowner’s fields. And it was struck on the basis that three-quarters of the watercourse would go to the landowner and three-quarters of what was left would go to them. This arrangement seemed fair to the eyes of Fontamara’s cafoni,hence their surprise when they later found out that very little water was reaching the village, and they had to start battling for their rights. It took me years to understand why my father wanted me to read this book. I now know that it was his own way of instilling in me a series of important values (political and otherwise) that Fontamara as a novel beautifully represents. And among them was the empowering value of education.

Second, the Italian state school system. I cannot stress enough how proud I am of the education that this system gave me throughout. I grew up, as I said, in a small village where there was only a primary school. For my secondary school, I went to a liceo classicoin the nearby town of Tivoli, where I had the opportunity to study a broad range of disciplines in the humanities (from Latin and ancient Greek to Italian literature, biology, history of art, and history). Philosophy was a compulsory subject for the final three years and I still remember the day my philosophy teacher introduced us to Plato’s theory of knowledge as recollection in Meno. It was one of those defining moments in my upbringing. I spent the long hot Italian summers eagerly reading Plato’s dialogues, among other philosophy books. I loved physics too and I read several popular science books by myself. When I had to decide what to read at the University of Rome “La Sapienza”, the choice for me came down to either physics or philosophy. (The Italian university system at the time did not allow students to combine physics and philosophy, or virtually any subject with any other). My almost instantaneous love for philosophy won in the end. Then I discovered that there was this thing called philosophy of science as part of the undergraduate degree programme in Philosophy, and I ended up specialising in it and writing my Laureadissertation in the area of history and philosophy of physics (on the Bohr–Einstein debate on the incompleteness of quantum mechanics). But obviously there was still a very long way for me to go (and very much into uncharted territories too).

European freedom of movement was the third element that allowed me to become a philosopher. Coming from a village in Italy, being an only child, and a woman, the idea of me going abroad to study for a PhD was practically unheard of. And once again, had it not been for the value my parents placed on education, as well as for the possibility of free movement across Europe, I most certainly would never have landed in the UK.

And here I am, still in the UK, and now Full Professor at the University of Edinburgh, twenty years later. My story is a story of “European social mobility”. A story like thousands of others. A story that is worth telling because this is also what Europe stands for, for myself and for my generation.

[Pauli]

3AM: Your very first work was about a philosophical issue that arises from Pauli’s exclusion principle. Can you begin by sketching what this principle is and why it is so important?

MM:My work on Pauli’s principle goes back to my graduate years. I came to the LSE to pursue a degree in history and philosophy of physics, building on my earlier research on the Bohr–Einstein debate for my undergraduate degree at the University of Rome. I had come across Wolfgang Pauli’s work in the context of the literature on Bohr’s Copenhagen interpretation of quantum mechanics. And I was struck by Pauli’s exclusion principle, on which surprisingly little had been written at the time in the field of history and philosophy of physics. It became my PhD topic. The principle, in its simple original form, says that in nature no two electrons can be in the same dynamic state. In its later form—due to Fermi and Dirac—the principle is expressed in terms of (antisymmetric) states for a system of indistinguishable half-integral spin particles.

The principle was crucial to explain the electronic distribution that underpins atomic spectra and the chemical properties of elements in the periodic table. But it also governs the distribution of nucleons inside atoms, which in turn explains a variety of phenomena in nuclear physics (from radioactive phenomena to the stability of matter, more generally). The principle applies to the most fundamental particles too, the quarks inside nucleons. It was this mind-boggling applicability of Pauli’s exclusion principle (from quarks to electrons and nucleons) that I found fascinating.

Something caught my attention when I started working on the principle (back in 1998). Looking at Pauli’s scientific correspondence and the way he originally introduced the principle in a letter to Alfred Landé in 1924, it was clear that it was a purely phenomenological rule to explain some puzzling phenomena in spectroscopy on which Pauli and colleagues had been working for years. Heisenberg referred to it teasingly as Pauli’s “Verbot”; and it was only with Dirac that it became known as “Pauli’s exclusion principle” in 1926. How did a phenomenological rule eventually become a scientific principle? This was the question that prompted my PhD research and eventually led to my book.

 

 

3AM: What’s the answer to this question? And how does the history of the Pauli principle help us understand what scientific principles are more generally?

MM: In my monograph on Pauli’s principle, I gave a historico-philosophical account of what transformed the original phenomenological rule into a scientific principle. I reconstructed how the rule got gradually embedded into a growing theoretical structure and quantum-mechanical formalism: from the Fermi–Dirac statistics in 1926, to quantum field theory in the 1930s; and, most importantly, the role played by Pauli’s so-called “spin-statistics theorem” of 1940 in establishing the nomological validity of the principle for allhalf-integral spin particles. There is an important philosophical literature on laws of nature, with a variety of accounts ranging from David Lewis’s Humean Best System, to D.M. Armstrong’s necessitarian account, and dispositionalist views (e.g. Alexander Bird’s), among others. Each of these philosophical accounts takes a stance on whether (or not) laws of nature are necessary, or explanatory, or otherwise.  Each of them accounts for (or deflates) some relevant features of laws (their necessity, explanatory power, or else) through sophisticated philosophical moves.

But none of them addresses the kind of historical question that I had in mind at the time. Namely, and to reiterate, how did a purely phenomenological rule become a scientific principle (and a fundamental one too)? This historical question is simply not contemplated in the current philosophical literature on laws of nature. One might argue that this is more of a question for historical epistemology than for contemporary philosophy of science. Or better, it is more an HPS (i.e., history-and-philosophy-of-science) question than a properly philosophical question about what a law of nature is. And I felt I had to give a proper HPS answer to this question.  My answer in the end resonated with a long-standing Kantian and neo-Kantian tradition, which back in the early twentieth century had grappled with the kind of historical question I had in mind. I never regarded my work on Pauli’s principle as an attempt at answering the wider metaphysical questions: “What is a law of nature?”; or, “What are scientific principles?”. Instead, it was meant to answer the historico-epistemological question as to how we—as finite epistemic agents—can ever come to recognise some empirical rules qua scientific principles governing a wide range of phenomena in nature. 

3AM: The distinction between regulative and constitutive principles is important in your analysis of Pauli’s principle. And, as you just said, you link this to a Kantian and neo-Kantian tradition. Could you sketch for us why you see Pauli’s principle as regulative and not constitutive?

MM: The distinction between regulative and constitutive principles can be found in Kant, and in much of the neo-Kantian literature. In contemporary Kantian approaches to philosophy of science, this distinction features in a debate between Michael Friedman and Gerd Buchdahl, for example, where the former defended the importance of constitutive principles and the latter offered a reappraisal of regulative principles in their respective readings of Kant. Very briefly, the debate over regulative and constitutive principles begins with the following question. How can we—as epistemic agents—come to encounter nature as lawful? Which epistemic faculty underpins our ability to recognise that some empirical regularities are not just accidentally so, but are effectively the manifestation of nature’s lawfulness?

This is an epistemological question, not a metaphysical one. It is a question about usas epistemic agents capable of knowing nature not as a contingent aggregate of appearances but as a lawful system. It is a genuine Kantian question (or, if you like, it is a Kantian way of asking a question about laws of nature), because it does not put the metaphysical cart in front of the epistemological horse, so to speak. And the typical Kantian answer to this question takes us right to the heart of Kant’s Critical philosophy. The Kantian answer goes roughly as follows.

There are two main faculties delivering on nature’s lawfulness: the faculty of understanding and the faculty of reason (or what later—in the third Critique—Kant referred to as the faculty of reflective judgment). The understanding offers constitutive principles, i.e. principles that play a constitutive role in our experiencing nature as lawful. Some Kant interpreters (Friedman, for example) have extensively argued for the importance of causality as a principle of the faculty of understanding that plays a constitutive a priori role in shaping and informing a variety of lower-level empirical causal laws (e.g., think of Newton’s second law, f=ma, as an example of an empirical law that causally links the notion of force with the notion of acceleration). Other Kant interpreters have lamented that such an emphasis placed on constitutive a priori principles overlooks the important role of regulative principles in his work, to be found primarily in his discussion of the faculty of reason and, later, the faculty of reflective judgment.

In the Critique of Judgment, for example, Kant is concerned not with causal laws in physics but rather with what he calls the purposiveness of nature from the point of view of the life sciences. And in this context, regulative principles play a key role. For they provide rules (from the Latin “regula”) for the correct empirical use of the faculty of understanding (as Kant points out already in the Appendix to the Transcendental Dialectic in the Critique of Pure Reason). In a way, regulative principles play an equally important role within Kant’s overall system of knowledge. They complement constitutive principles in addressing the question about nature’s lawfulness. For example, in the third Critique, we are told how it is the task of the faculty of reflective judgment (and its regulative principles) to subsume empirical lower-level regularities under higher-order (yet still empirical) ones. Kant’s principle of “systematicity” is a regulative principle that offers rules for organising and systematising our empirical knowledge into a lawful “system”.

Thus, going back to the history of Pauli’s principle, one can tell a similar story about how the principle accomplished a regulative (rather than a constitutive) function. The principle originated in the 1920s as a simple phenomenological rule to explain puzzling spectroscopic anomalies (e.g., the anomalous Zeeman effect and the alkali doublets, among others), and got gradually embedded into a growing theoretical framework. In 1940, thanks to the spin-statistics theorem, the nomological validity of the principle was extended to any half-integral spin particles, not just electrons. Looking at the history of Pauli’s principle, it seemed to me that there was a clear story to tell about the gradual “systematization”, if you like, of empirical lower-level knowledge claims into a proper system of knowledge. And it was only as a result of this (Kantian in spirit) process of systematization that the humble empirical rule became a fundamental scientific principle.

Thus, in my monograph on Pauli’s principle (which essentially came out of my PhD thesis) I wanted to tell a Kantian story about the origin and historical evolution of a scientific principle. It was a story that intentionally side-tracked all the ongoing debates in the metaphysics of science about whether laws are Humean regularities; or necessitation relations between universals; or otherwise.

3AM: In more recent times, you have written more extensively about Kant and the laws of nature. What are laws of nature for Kant? And what is “the Kantian problem of inference”, as you call it?

MM: My earlier historical work on Pauli’s principle led me on a journey back to Kant’s own philosophy of natural science, which is a world of its own and an inexhaustible treasure trove of ideas. Kant’s view on the lawfulness of nature is central to his Critical project. For he regards the faculty of understanding as the ultimate source of the lawfulness of nature. In Kant’s view, our ability to see, for example, two appearances (e.g., my cup of coffee falling and a stain forming on the floor) as causally connected (and not just as some kind of Humean juxtaposition of events) is due to one of our principles of the faculty of understanding, namely causality. Given this a priori principle of the faculty of understanding, Kant maintains that it is possible for us to causally order the manifold of appearances according to the cause–effect template (i.e., it is the cup of coffee falling that caused the stain on the floor). Moving on to a less mundane example, Newton’s second law might be regarded as an empirical causal law that instantiates Kant’s a priori principle of causality.

In 2012–15 I was the Principal Investigator of a Leverhulme Trust international network entitled Kantand the Laws of Nature: Lessons from the History of the Physical and the Life Sciences of the Eighteenth Century. The idea was to offer a systematic exploration of Kant’s view of the laws of nature, its historical context, and its legacy for contemporary debates in philosophy of science and in the sciences (the public outreach activities of the project featured scientists—including Nobel prize winner Professor John O’Keefe—giving lectures at the Royal Institution in London). A series of research outputs emerged from this project. The principal one was a book published in 2017 by Cambridge University Press entitled Kant and the Laws of Nature, which I co-edited with Angela Breitenbach. In this book, I have a chapter called “Grounds, modality and nomic necessity in the Critical Kant”, where I lay out what I call the “Kantian problem of inference”, echoing Bas van Fraassen’s famous objection against D.M. Armstrong’s necessitarian view of the laws of nature.

In brief, the problem is how to infer from the necessity of a priori principles of the understanding to the nomological necessity of empirical causal laws, all the way down to the necessary lawlike occurrences in nature. In other words, how does the inference proceed from the a priori necessity of Kant’s principle of causality (i.e., “All alterations occur in accordance with the law of the connection of cause and effect”) to the nomological necessity with which empirical causal laws (say, Newton’s laws) prescribe that, for example, high tide mustoccur as a result of the Earth–Moon alignment today at 11.35 am on Cramond Island? The problem originates from the way Kant presents the understanding as “prescribing” laws a priori to nature “as the sum total of all appearances” (B163) in the first Critique. Why does Kant use such strong wording (“prescribe”)? And how can the understanding possibly prescribe the way nature ought to be? Does Kant really mean that the understanding has a purchase on nature?  The Kantian problem of inference is puzzling both metaphysically and epistemologically.

From the metaphysical point of view, the obvious option would be to bypass altogether the problem of inference by appealing to Kant’s transcendental idealism. After all, the understanding can only prescribe laws to nature in a purely formal sense (qua natura formaliter spectata, as Kant calls it) and not in any real (or material) sense. In other words, the understanding can at best causally order spatio-temporal appearances(which depend on us because for Kant space and time are a priori forms of intuitions) without really “prescribing” the way nature ought to behave. But if this were Kant’s considered answer to the problem of inference, he would not seem to fare much better than Hume on the problem of induction: nothing guarantees that the tide will indeed occur on Cramond Island at the next Earth–Moon alignment. The laws that the understanding is said to “prescribe” to nature would only be a façon de parler,philosophically no more robust than Hume’s idea of a necessary connection in nature.

From an epistemological point of view, the problem of inference is similarly puzzling. Kantseems to be saying that empirical causal laws cannot be completely derived from the categories, although “they all stand under them” (B165). Again, if particular empirical causal laws (say, Newton’s law of gravity behind the phenomenon of tides) do not completely derive from the understanding (nor from experience either), where does their nomological necessity originate? And how can we claim to cognize it?

To address the Kantianproblem of inference, I went back to Kant’s Lectures on Metaphysics, translated into English in an excellent edited collection by Karl Ameriksand Steve Naragon. Much as we think of Kant’swork as anti-metaphysical, he lectured regularly on metaphysics, and notes taken by his students over a span of twenty years or so show a surprising continuity of topics and themes. And in that context, one can find references to what in modern terminology we might call “ground(s)”—Kant called it in Latin ratio(plural rationes). He distinguished among three kinds of grounds: what he called ratio cognoscendi,ratio essendi,and ratio fiendi (the ground of knowing, the ground of being, and the ground of becoming). The latter are the ones that I focus on in my answer to the problem of inference on Kant’s behalf.

Kant understood “grounds of becoming” as causal grounds for the necessary occurrence of their consequents. He used the expression “natures” often interchangeably with “grounds of becoming”; and distinguished “natures” from what he called “essences”, which, in his view,  give only the grounds of the possibility of things but not the grounds of their actuality. By appealing to the “natures of things” as causal grounds, Kant could avail himself of a series of modal moves that allowed him to address the problem of inference—or so I have argued. For example, he could maintain that given a ground of becoming, some essential properties are posited. (The ability of matter to exercise an attractive force on other pieces of matter is one example of essential property that is grounded in the “nature” of matter.) And with essential properties in place, the dispositional behaviour of objects is also posited (e.g., the disposition of any lump of matter to attract another one), which ultimately grounds the necessary connection of causes and effects within nature.

Thus, on the interpretive reading I have suggested, Kant endorsed a sophisticated and nuanced metaphysical view, rather than spearheading a complete disengagement with metaphysics. In my view, Kant can legitimately defend the claim that the understanding prescribes laws to nature because the understanding provides templates (say, the cause–effect template expressed by the principle of causality) which we learn to fill in from experience. Kant clearly says that “we become acquainted with the powers of things bit by bit in experience” (28: 553), although we can never come to know the real essences or the natures of things. By experience we become acquainted with attractive and repulsive forces, notwithstanding our lack of knowledge of their causal grounds. By experience, we also learn how to track multiple effects under a common power (e.g., as when we track planetary motion as well as tidal motion down to a single attractive force as an essential power of material bodies). Thus, the lawfulness of nature is not just a projected lawfulness that the understanding imposes onto an aggregate of appearances without any real purchase on nature. Instead, I contend, the lawfulness of nature for Kant resides in the “natures” of things, which—although unknowable—ground nonetheless a variety of lawlike phenomena in nature.

3AM: Much of your reading of Kant on lawsemerges from his lectures on metaphysics. How do you see the relationship between philosophy of science, metaphysics, and science more generally?

MM: Kant featured prominently in my undergraduate studies in Philosophy at the University of Rome “La Sapienza”. He was read very much through the lenses of an all-pervasive idealist tradition (profoundly influential in Italy), which left no room for metaphysics. Thus, in a way, my interest in how metaphysicsmay helpfully inform discussions about science, philosophy of science, and even Kant’s philosophy of nature is very much an “acquired” philosophical taste.

I am interested in how scientific knowledge (and related problems thereof) tells us something about the metaphysicsof nature (see, for example, how the Kantian problem of inference may lead us unexpectedly to the notion of “grounds” in Kant). Modern science engages in metaphysicswhenever it asks questions about what there is. For example, some cutting-edge scientific research at the moment deals with important metaphysical questions. Do dark matter and dark energy exist? Are there supersymmetric particles? It is ultimately the task of science to find answers to these questions.  But it is the task of philosophers of science to investigate the metaphysical underpinnings of scientific methodsand epistemic approaches designed to answer these questions. (For example, what kind of models do scientists devise to search for dark matter and dark energy? What kind of data can be brought to bear on these models? And how do models, data, and statistical methods reliably track what there might be?)

3AM: You are currently the Principal Investigator of a five-year ERC-funded Consolidator Grant entitled Perspectival Realism: Science, Knowledge and Truth from a Human Vantage Point. Can you tell our readers what perspectival realism is and why it is important?

MM: Perspectival realism is the perfect illustration of the way in which metaphysics, science, and philosophy of science are intertwined. The term “perspectival realism” is borrowed from Ron Giere, who in his 2006 book Scientific Perspectivism used it to label the kind of realism he sees as compatible with scientific perspectivism. This latter approach maintains that our scientific knowledge is historically and/or culturally situated: it is the product of the historical and/or cultural traditions in which scientific representations, modelling practices, data gathering, and scientific theories are formulated. Stated in this way, the position is not new. That scientific knowledge is historically and culturally situated has become a common view pretty much since the time of Hanson and Kuhn in philosophy of science. But scientific perspectivism has deeper roots, going back to Kant and to the idea of knowledge from a human point of view (the only point of view that is epistemically accessible to us).

Granted this tradition, the metaphysical question that looms large is then: how can one be a realist about science (and believe, for example, that scientific theories are approximately true) while also acknowledging that our scientific knowledge is inevitably situated? The epistemic humility behind perspectivism seems to be in stark contrast with the God’s-eye view presupposed by the realist quest for truth. Giere gives his own considered answer to this question in terms of a mitigated kind of realism. In his view what a realist can at most claim is that “according to this highly confirmed theory (or reliable instrument), the world seems to be roughly such and such” (Giere 2006, pp. 5–6). Whether realism so stated still deserves the title of realism (or whether perspectival realism risks being a misnomer for some kind of perspective-relativity) is precisely what is at stake in this debate about perspectivism and realism.

In my project on Perspectival Realismfunded by the European Research CouncilI am probing deeper into the vexed issue of how to reconcile perspectivism with realism. In the monograph I am currently writing, I want to defend a version of perspectival realism that is worth the title of realism and that does not just pay lip service to perspectivism. A form of perspectival realism that takes seriously the Kantian lesson about the human standpoint but sees it as opening up resources for our search for truth (rather than imposing limits to our ability for knowledge). My final goal is to deliver a metaphysics of nature from a human vantage point, a metaphysics that does justice to our scientific achievements while also celebrating the situated and pluralistic nature of our scientific knowledge.

3AM: Your research has a distinctive multidisciplinary nature. For example, in your current project, you are combining fieldwork at CERN and at the Dark Energy Survey with historical research on the history of the electron to elaborate on perspectival realism. What challenges does this kind of interdisciplinary research face? And what are the intellectual rewards?

MM: Going back to my observation above about how I see epistemological problems driving metaphysics (rather than the other way around), my approach to perspectival realism starts with our scientific knowledge. In what sense is our scientific knowledgesituated, perspectival, and pluralistic? And how can the perspectival nature of our knowledge foster (rather than hinder) our search for what might be real? These questions become pressing if one considers current research at CERN for new physics that might go beyond the Standard Model, for example. Or if one considers cosmological research (such as that currently done at the Dark Energy Survey among many other ongoing and planned cosmological surveys) to search for elusive entities such as dark matter and dark energy. These are two cutting-edge areas of research in contemporary physics where again the quest for realism is inevitably entangled with our limited, situated, and perspectival knowledge. It is entangled with the kind of modelling techniques, statistical methodologies, and theoretical and conceptual resources available to particular scientific communities at particular times. How can scientists devise effective strategies to answer the realist quest? How can they go beyond the accepted and entrenched models (e.g., the Standard Model in particle physics)? How can they find answers to questions concerning the existence and nature of dark matter and dark energy?

In this respect, the challenges that contemporary physicists are facing today do not differ from the challenges that, say, J.J. Thomson was facing in introducing his “corpuscle” (what we now call the electron) at the end of the nineteenth century; or the challenge of Lavoisier introducing “oxygen” in the context of the then well-accepted phlogiston theory in the eighteenth century. Thus, in my project, I explore what—echoing van Fraassen—might be called the prospective intelligibility of moving from accepted and well-entrenched systems of knowledge onto new territories, which might disclose brand-new (and even undreamt-of) entities. I believe that new light can be shed on most philosophical discussions about the epistemology and metaphysics of science if addressed from the point of view of scientific practice (of the past and present).

Of course, there are significant challenges associated with this kind of interdisciplinary research. The first is to be able to meaningfully bring scientific practice to bear on discussions about realism and perspectivism in science. Often enough in my area (the history and philosophy of science) there is a tendency to get lost in lengthy case studies that do not necessarily illuminate the philosophical issues at stake. The opposite risk is that the case studies become a vignette at the end of a self-standing piece of philosophy. Being able to wear different hats depending on whether the interlocutors are physicists, historians, or philosophers is methodologically very challenging, and it is also an intellectually risky enterprise. We live in an era where not even within a single discipline (say, philosophy) can scholars easily communicate or build bridges because of the very different languages, intellectual priorities, and research goals present in different sub-fields.

Interdisciplinary research is hard work; and only very recently has it been re-evaluated—our academic institutional system favours specialisms and narrowly defined expertise over the ability to speak different disciplinary languages and bring communities that do not normally interact in dialogue with one another. Yet I am a firm believer in the value of interdisciplinary research and in the importance of crossing those bridges and bringing communities together (a topic that I addressed in my Royal Society 2017 Wilkins–Bernal–Medawar Medal Lecture).I believe that the future of our educational system depends on our ability to deliver knowledge that equips future generations with the value of interdisciplinary research so as to tackle some of the pressing challenges that both the sciences and the humanities are facing.

3AM: In a society where issues about pluralism and perspectivism have political resonances and implications for public discourse, how do you see your work as contributing to ongoing debates about truth, evidence, and pluralism in science?

MM: Scientific pluralism and scientific perspectivism have a long-standing respectable tradition. They began to gain traction in the 1960s/1970s when—as Giere nicely puts it in the introduction to Scientific Perspectivism—pluralism and perspectivism were rediscovered among discontent over the misuse of technological resources for military purposes (in the Vietnamese war, for example) and new attention paid to marginalised voices in science and in philosophy. Yet, in our time, when the very notions of “evidence” and “scientific fact” get questioned in prominent quarters, I think philosophers of science with pluralist and perspectivist leanings have a social responsibility they never had before. It is incumbent on us all (and on the philosophical narratives we produce) to make sure that the values of pluralism and perspectivism in science are neither misused nor misunderstood in public discourse. Being pluralist and perspectivist about science does not entail that scientific evidence is malleable. Nordoes it entail that there might be different perspectival facts, or that truth is relativized toperspectives. Being pluralist and perspectivist about science does notmake truth some kind of convenient commodity. I am very concerned by the way in which discussions of pluralism and perspectivism in science risk being translated into worrisomely distorted caricatures, and how these caricatures might ultimately feed into public distrust of science. I think philosophers of science have a social responsibility to rectify these caricatures, to call them out, and to speak up for what scientific perspectivism and pluralism really stand for: namely, a philosophically richer image of how scientific inquiry delivers on the realist goal of gathering evidence and searching for truth, even in the absence of a God’s-eye view on nature.

3AM:And, to close, for the readers here at 3AM, are there five books you could recommend to take us further into your philosophical world?

MM: Many books come to my mind, and many have been influential for my philosophical upbringing (I have already mentioned a few authors above). But here is my list of five relatively recent books by excellent women and men philosophers that I would recommend to the readers of 3AM Magazine:

Helen Beebee (2006) Hume on Causation(Routledge).

This is an important book that explores metaphysical issues about causation. Hume is typically portrayed as a sceptic with regard to causation. In this book and related publications on the topic, Beebee does an excellent job in setting the record straight and in clarifying the projectivist interpretation of Hume on causation.

Eric Watkins (2005) Kant and the Metaphysics of Causality (Cambridge University Press)

This book will make you think again about Kant if you grew up (as I did) within a cultural tradition that somehow shunned discussions of metaphysics in the context of Kant’s philosophy. You will be pleasantly surprised to find out how much Kant engaged with the metaphysics of causality and how much importance he ascribed to the notion of “real grounds” in the context of his engagement with the Leibnizian tradition.

 

Bas van Fraassen (2008) Scientific Representation: Paradoxes of Perspective (Oxford University Press).

This is a wonderful journey in the perspectival nature of our scientific representations. Van Fraassen tells us a compelling story about the situated nature of our measurement techniques and modelling practices, a story that shows very many similarities with perspectival drawings in art, and whose roots can again be traced deep into Kant, Reichenbach, and the neo-Kantians more generally.

Margaret Morrison (2015) Reconstructing Reality: Models, Mathematics and Simulations (Oxford University Press).

This book sets a very high standard for what good work in philosophy of science ought to look like. Morrison engages with scientific practice and the details of modelling and computer simulations in contemporary physics (especially in the discovery of the Higgs boson). The book puts forward pressing arguments against perspectivism that I have mulled over for some time.

Sandra Mitchell (2009) Unsimple Truths (University of Chicago Press).

This is another example of how scientific practice informs contemporary discussions about pluralism and perspectivism in science. Mitchell considers complex systems in biology(rather than physics) and champions what she calls integrative pluralism as a way of expanding our understanding of the natural world.

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